RM85 vs RM125?

Hey i do not no what bike to get i am 5ft 12years old i am riding a 70cc now im using the bike on a farm but i wont a bit of power to rip through the dirt and will i be and to fit on it and control in after a few weeks my uncle says i might be able to ride the 125 but my cousin said i cant which one do i get????but i have to keep it untill i am 15

try the 85cc mate, if you want a little extra power try to find one that's had a Worx kit fitted..100cc in total, nice on a big wheeled RM, lots of power and the bike is nice and light,The 125 would be a bit of a hand full for you to throw around, its a lot heavier than the 85 or 100.The 100cc will burn 125's :o)Good luck !